JP5007280B2 - Method for producing optical waveguide for touch panel and optical waveguide for touch panel obtained thereby - Google Patents

Description

The present invention relates to a method for manufacturing an optical waveguide for a touch panel and an optical waveguide for a touch panel obtained thereby.

  A touch panel is an input device for operating a device by directly touching a screen such as a liquid crystal display with a finger or a dedicated pen. The configuration of the touch panel includes a display that displays operation contents and the like, and a detection unit that detects a touch position (coordinates) of the finger or the like on the screen of the display. Then, information indicating the touch position detected by the detection means is sent as a signal, and an operation or the like displayed at the touch position is performed. Examples of devices using such a touch panel include ATMs at financial institutions, ticket vending machines at stations, and portable game machines.

  As a means for detecting a touch position of a finger or the like on the touch panel, one using an optical waveguide has been proposed (for example, see Patent Document 1). That is, the touch panel has an optical waveguide installed on the peripheral edge of the screen of a square display. Then, a large number of lights are emitted from the emission part of the optical waveguide on the light emission side installed on one side of the display screen toward the other side in parallel with the display screen. However, it is made to enter into the incident part of the optical waveguide of the light-incidence side installed in the other side part. With these optical waveguides, the emitted light runs in a grid pattern on the display screen. In this state, when the finger touches the screen of the display, the finger blocks a part of the emitted light, and the finger touches the blocked part by sensing the blocked part with the light incident side optical waveguide. The position of the part can be detected.

On the other hand, light emitted directly from the optical waveguide into the air diverges radially. In this state, the light transmission efficiency is low, and the position touched by the finger cannot be accurately detected. Therefore, an optical transmission device with improved optical transmission efficiency has been proposed (see, for example, Patent Document 2). This conventional optical transmission apparatus is schematically shown in FIGS. 7 (a) and 7 (b). This optical transmission device includes an optical waveguide 10 and a lens body 20. The lens body 20 includes a placement surface portion 21 on which the optical waveguide 10 is placed, and a thick belt-like lens 22 that is formed to protrude from the tip edge portion of the placement surface portion 21. The lens surface (the surface on the right side in the figure) of the belt-like lens 22 is formed in an arc shape in a side sectional view (see FIG. 7B) that warps outward. The optical waveguide 10 has an under-cladding layer 12, a core 13, and an over-cladding layer 14 laminated in this order. The tip of the core 13 is formed into a lens portion 130 having a semicircular shape in plan view. Formed and exposed to the outside. The lens surface (tip surface) of the lens unit 130 is formed in a circular arc shape in plan view (see FIG. 7A) that warps outward. In such an optical transmission device, when the light S emitted from the core 13 passes through the lens portion 130 at the distal end portion of the core 13, due to the refraction action of the semicircular lens portion 130 in plan view, the placement surface portion described above. Divergence in a direction (lateral direction) parallel to the mounting surface 21 is suppressed. Thereafter, when the light S passes through the belt-like lens 22 of the lens body 20, the light S diverges in a direction (longitudinal direction) perpendicular to the placement surface portion 21 due to the refracting action of the belt-like lens 22 having an arcuate side view. Is suppressed. When such an optical transmission device with high optical transmission efficiency is used as an optical waveguide for a touch panel, the position touched by a finger on the touch panel can be accurately detected.
US2004 / 0201579A1 JP 2003-4960 A

  However, in the above conventional optical transmission device, the optical waveguide 10 and the lens body 20 are bonded together in a state where the lens portion 130 at the tip of the core 13 of the optical waveguide 10 and the belt-like lens 22 of the lens body 20 are accurately aligned. There is a need to. If the alignment is not performed accurately, the divergence suppression of the light S on the light emission side is not performed properly, and the position of the finger touching the display screen cannot be detected accurately. However, the precise alignment is difficult because precision is required, and it takes time and effort to achieve it.

The present invention has been made in view of such circumstances, and an object thereof is to provide a method for manufacturing an optical waveguide for a touch panel that does not require alignment between the optical waveguide and a lens body, and an optical waveguide for a touch panel obtained thereby . To do.

In order to achieve the above object, the present invention comprises a core patterned on the surface of a substrate and an overcladding layer formed by molding in a state of covering the core, and a screen peripheral portion of a touch panel display The end of the core that emits light is positioned on one side of the screen of the display, the end of the core that receives the emitted light is positioned on the other side of the display screen , end of the core for emitting the light is formed on the first lens section while exposed to the outside air Te deficiency recess smell of the over cladding layer, in plan view which bulges lens surface at the first lens unit toward the outside is formed in a circular arc shape, the portion of the over cladding layer facing at a lens surface and the gap of the first lens portion is formed in the second lens unit corresponding to the first lens unit A method of lens surface at the second lens unit to produce a side sectional view arcuately been formed filter touch panel optical waveguide which bulges outwardly, the mold used for the molding of the over cladding layer A concave portion having a mold surface corresponding to the surface shape of the overcladding layer is formed, and one side portion of the concave portion is formed in the curved surface shape of the second lens portion. The manufacturing method of the optical waveguide for a touch panel in which the formation of the over cladding layer is performed through the following steps (a) to (d) is a first gist.
(A) A step of forming an uncured photosensitive resin layer for forming an overcladding layer on the surface of the substrate in a state where the core is covered.
(B) The concave portion of the molding die is pressed by pressing the concave portion of the molding die against the photosensitive resin layer in a state where the curved surface portion of the concave portion of the molding die is disposed so as to correspond to the first lens portion of the core. A step of closely contacting the opening surface of the substrate to the surface of the substrate.
(C) A light-shielding mask is placed on the surface portion of the molding die corresponding to the defective recess formation scheduled portion, and in that state, the photosensitive resin layer is exposed with irradiation rays through the molding die, and the exposed portion Is a process of forming an overcladding layer by curing.
(D) After demolding, the unexposed portion of the photosensitive resin layer corresponding to the light shielding mask is removed by development to form the defective recess, and the first lens portion of the core is formed from the defective recess. The process of exposing to the outside air.

Further, the present invention is an optical waveguide for a touch panel obtained by the above-described method for manufacturing an optical waveguide for a touch panel, wherein the core is patterned on the surface of the substrate, and the photosensitive is formed by molding in a state of covering the core. a sexual resin of the over-cladding layer, the ends of the core for emitting light is formed in the first lens unit, the lens surface is formed in plan view an arc shape which bulges outwardly in the first lens unit A portion of the overcladding layer corresponding to the first lens portion of the core is formed in a defective concave portion that is a removal mark by development, and the first lens portion is exposed to the outside air in the defective concave portion, and the first lens A portion of the over clad layer facing the lens surface of the portion with a gap is formed to form a second lens portion corresponding to the first lens portion, and the lens surface in the second lens portion is outside. The touch panel optical waveguide which is formed on a side cross section arc shape bulges to the second aspect.

In order to solve the above problems, the inventor forms an end of the core in the first lens unit, and then forms the second lens unit as a part of the over cladding layer when forming the over cladding layer. It was conceived to be formed in front of the first lens part. In this case, since the core and the over clad layer are originally integrated, the optical waveguide for a touch panel according to the present invention has the first lens portion and the over clad layer at the core end when the over clad layer is formed. The second lens portion which is a part of the second lens portion is aligned.

In the method for manufacturing an optical waveguide for a touch panel according to the present invention, an end portion of a core that emits light is formed in a first lens portion having a lens surface having a circular arc shape in plan view that warps outward, and the first lens portion. open the lens surface and the gap, the second lens unit having a side section view an arcuate lens surface which bulges outwardly, is formed as part of the over cladding layer. Therefore, in the method of the touch panel optical waveguide of the present invention, at the time of forming the over cladding layer, and a second lens unit consisting of a portion of the first lens portion of the core end portion and the over cladding layer, automatically It can be in an aligned state. For this reason, the alignment operation | work with the said 1st lens part and a 2nd lens part can be made unnecessary, and productivity can be improved.

Further, the first lens unit, a substantially fan shape gradually widened toward the end face of the second lens portion, the circular surface at the substantially fan-shaped when you formed on the lens surface, the The light that has entered the widened portion from the base portion of the first lens portion spreads substantially uniformly along the shape of the widened portion, and the light reaches the lens surface of the end face substantially uniformly. For this reason, wide light can be emitted from the lens surface of the first lens portion in a state where the light intensity is substantially uniform in the width direction. As a result, even if the position of the finger touching the display screen slightly deviates from a predetermined position on the touch panel, the position of the portion touched by the finger can be properly detected by the wide light.

Further, formed in the third lens unit in a state where the end portion is exposed to the outside air Te other defects recess smell above Kio over bar cladding layer of the core entering the emitted light, the lens surface at the third lens unit It is formed in plan view an arc shape which bulges outwardly, formed in the fourth lens unit portion of the over cladding layer facing at a lens surface and gaps of the third lens unit corresponds to the third lens unit A method for manufacturing the optical waveguide for a touch panel, wherein the lens surface of the fourth lens portion is formed in an arc shape in a side sectional view that warps outward, and is used for molding the over clad layer The mold is made of a material that transmits radiation, a recess having a mold surface corresponding to the surface shape of the over cladding layer is formed, and the other side of the recess is the lens curved surface of the fourth lens unit. Jo to have been formed, the formation of the over cladding layer, when it is performed via the process of the following (e) ~ (h), as well as the light emitting side of the first and second lens portions When the over clad layer is formed, the third lens portion and the fourth lens portion can be automatically aligned, and productivity can be improved.
(E) A step of forming an uncured photosensitive resin layer for forming an overclad layer on the surface of the base body in a state of covering the core.
(F) The concave portion of the molding die with respect to the photosensitive resin layer in a state where the lens curved surface shape portion of the fourth lens portion of the concave portion of the molding die is disposed so as to correspond to the third lens portion of the core. And pressing the opening surface of the recess into close contact with the surface of the substrate.
(G) A light-shielding mask is placed on the surface portion of the mold corresponding to the other defective recess formation scheduled portion, and in that state, the photosensitive resin layer is exposed with irradiation rays through the mold, A step of curing the exposed portion to form an overcladding layer.
(H) After demolding, by development, the unexposed portion of the photosensitive resin layer corresponding to the light-shielding mask is removed to form the other defective concave portion, and the third lens of the core is formed from the defective concave portion. The process of exposing the part to the outside air.

Further, the third lens unit, when the fourth gradually widening toward the end surface of the lens portion a substantially fan shape, that form a circular surface at the substantially fan shape to the lens surface, the Since the lens surface of the third lens portion is wide, it is easy for light to enter the lens surface of the third lens portion. For this reason, light transmission efficiency can be improved and the position of the finger touching the screen of the display can be detected more accurately on the touch panel.

Touch panel optical waveguide of the present invention, because produced by a production method of the optical waveguide for the touch panel, it is suppressed divergence of the light emitted from the end face of the core, to accurately detect the position of a finger having touched the display screen of the display be able to.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

1A to 1C show a first embodiment of an optical waveguide for a touch panel according to the present invention. As shown in FIG. 1A, the touch panel optical waveguide W ₁ of this embodiment is formed in a rectangular frame shape in plan view. One L-shaped part constituting the quadrangular frame shape is an optical waveguide part A on the light emitting side, and the other L-shaped part is an optical waveguide part B on the light incident side. The touch panel optical waveguide W ₁ has a plurality of cores 3A and 3B, which are light paths, on predetermined portions of the surface of the undercladding layer (substrate) 2 formed in a rectangular frame shape. It is formed in a pattern extending from the predetermined portions a and b of the outer edge portion to the inner edge of the L-shaped portion [screen side of the display 11 (see FIG. 2)] in parallel at equal intervals. In addition, the number of cores 3A formed in the light output side optical waveguide portion A and the number of cores 3B formed in the light incident side optical waveguide portion B are the same. Furthermore, the end surface of the light emitting side core 3A and the end surface of the light incident side core 3B are in a state of facing each other. In this embodiment, as shown in FIG. 1 (b) [enlarged view of the round portion C in FIG. 1 (a)] and FIG. 1 (c) [XX sectional view in FIG. 1 (b)]. The end portion of the light emitting side core 3A is formed in the substantially fan-shaped first lens portion 31, and the light incident side core 3B is formed in the third lens portion (33). Since these shapes and the like are the same, in FIGS. 1B and 1C, the first lens portion 31 and the third lens portion 33 are described together (the same applies to other portions). . That is, the first and third lens portions 31 (33) gradually widen toward the end face (the right end face in the figure) to form a substantially fan shape, and the arcuate surface portion of the substantially fan shape is curved outward. The lens surface 31a (33a) has a circular arc shape in plan view. The core 3A (3B) including the first and third lens portions 31 (33) is formed to have a uniform height. An over clad layer 4 is formed at a uniform height on the surface of the under clad layer 2 so as to cover the core 3A (3B) portion excluding the first and third lens portions 31 (33). The first and third lens portions 31 (33) protrude from the end 4b of the over clad layer 4 and are exposed to the outside air. Further, a second lens portion 42 formed of an extension portion that is a part of the over clad layer 4 with a gap from the lens surface 31 a of the first lens portion 31 extends along the formation row of the first lens portion 31. A band is formed on the surface of the under cladding layer 2. Similarly, a fourth lens portion (44) formed of another extension portion of the over clad layer 4 with a gap from the lens surface (33a) of the third lens portion (33) is formed in the third lens portion 33. Are formed on the surface of the under-cladding layer 2 in the form of a band along the formation row. The end surfaces (right end surfaces in the drawing) of the second and fourth lens portions 42 (44) are formed as lens surfaces 42a (44a) having a circular arc shape in a side sectional view that warps outward. In FIG. 1A, the cores 3A and 3B are indicated by solid lines and chain lines, and the thicknesses of the solid lines and chain lines indicate the thicknesses of the cores 3A and 3B, and the numbers of the cores 3A and 3B are indicated. The illustration is omitted.

As shown in FIG. 2, the quadrangular frame-shaped optical waveguide for touch panel W ₁ is installed along the quadrangle at the periphery of the screen so as to surround the screen of the quadrangular display 11 of the touch panel 10. Then, at a predetermined portion a at the outer edge of the optical waveguide portion A on the light emitting side, a light source (not shown) such as a light emitting element is connected to the core 3A, and the outer end of the optical waveguide portion B on the light incident side. At a predetermined portion b at the edge, a detector (not shown) such as a light receiving element is connected to the core 3B. In FIG. 2, as in FIG. 1A, the cores 3 </ b> A and 3 </ b> B are indicated by solid lines and chain lines, and the thicknesses of the solid lines and chain lines indicate the thicknesses of the cores 3 </ b> A and 3 </ b> B. The numbers are abbreviated. Further, in FIG. 2, only a part of the light S among many lights is shown for easy understanding.

  As shown in FIG. 3A [plan view] and FIG. 3B [XX sectional view of FIG. 3A], in the optical waveguide portion A on the light emitting side, the end portion of the core 3A The light S emitted from the light spreads substantially uniformly along the shape of the substantially fan-shaped widened portion due to the substantially fan-shaped shape of the first lens portion 31 at the end thereof. Further, the light S is transverse (left and right) with respect to the traveling direction of the light S due to the refracting action caused by the shape of the lens surface 31a (circular arc in plan view) of the first lens unit 31 [FIG. )]] Is suppressed. And the light S is radiate | emitted from the lens surface 31a of the 1st lens part 31 to an external air part in the wide state corresponding to the said lens surface 31a. At this time, since the light S is emitted to the outside air portion, the divergence is easily suppressed from the difference in refractive index between the first lens portion 31 and the outside air portion. Subsequently, the light S enters the second lens unit 42 from the back surface (surface opposite to the lens surface 42 a) 42 b of the second lens unit 42, and the shape (side) of the lens surface 42 a of the second lens unit 42. Divergence in the vertical direction (vertical direction) [see FIG. 3B] with respect to the traveling direction of the light S is suppressed by the refraction action caused by the arc shape in cross section. Then, the light S is emitted from the lens surface 42 a of the second lens unit 42. That is, on the light emitting side, the divergence in the horizontal direction or the vertical direction with respect to the traveling direction of the light S is suppressed by the refracting action of the two lens parts (the first lens part 31 and the second lens part 42). Thus, the light S is emitted from the lens surface 42a of the second lens unit 42 and travels along the screen of the display 11 (see FIG. 2).

  On the other hand, in the optical waveguide portion B on the light incident side, the light S that has traveled on the screen of the display 11 (see FIG. 2) travels in a direction opposite to the direction shown in FIGS. 3 (a) and 3 (b). . That is, the light S is incident from the lens surface (44a) of the fourth lens portion (44), and is caused by the shape of the lens surface (44a) of the fourth lens portion (44) (circular shape in a side sectional view). Due to the refracting action, the light S is focused further in the longitudinal direction with respect to the traveling direction of the light S. And the light S is radiate | emitted from the back surface [surface on the opposite side to a lens surface (44a)] (44b) of a 4th lens part (44) to an external air part. At this time, the light S is easily focused due to the difference in refractive index between the fourth lens portion (44) and the outside air portion by being emitted to the outside air portion. Subsequently, the light S efficiently enters the third lens portion (33) from the wide lens surface (33a) due to the substantially fan-shaped shape of the third lens portion (33). The light S is further focused in the lateral direction with respect to the traveling direction of the light S by the refraction action caused by the lens surface (33a) shape (arc shape in plan view) of the third lens portion (33). Is done. That is, on the light incident side, the light is focused in the vertical direction or the horizontal direction with respect to the traveling direction of the light S by the refractive action of the two lens parts [the fourth lens part (44) and the third lens part (33)]. In the state, the light S travels in the depth direction of the core (3B). In this embodiment, since the third and fourth lens portions (33) and (44) for converging and focusing the light S are formed on the light incident side, the first and first lens portions on the light emitting side are formed. Even if the two lens portions 31 and 42 do not emit light with the light constricted, the light transmission efficiency can be improved.

Since such light transmission is performed in the optical waveguide W ₁ for a touch panel shown in FIG. 2, the light S is transverse to the traveling direction on the screen of the display 11 of the touch panel 10 as shown in FIG. In a state where the vertical divergence is suppressed, the light travels in a lattice shape (in FIG. 2, only a part of the light S forming the lattice is shown for easy understanding). For this reason, when the finger touches the screen of the display 11 in this state, the position of the part touched by the finger can be accurately detected.

The optical waveguide for touch panel W ₁ that operates properly in this way includes the width D ₁ of the outside air part that exposes the first lens part 31 and the third lens part 33 in FIGS. 1A to 1C. The width (D ₂ ) of the exposed outside air portion is usually set within a range of 50 to 3000 μm. The width E ₁ of the gap between the lens surface 31a of the first lens portion 31 and the second lens portion 42 and the width (E ₂ ) of the gap between the lens surface 33a of the third lens portion 33 and the fourth lens portion 44 are as follows. Usually, it is set within a range of 10 to 20000 μm. Furthermore, the central angle (taper angle) α ₁ (α ₃ ) of the substantially fan-shaped widened portions of the first and third lens portions 31 and 33 is normally set within a range of 5 ° to 50 °.

Further, in the touch panel 10 shown in FIG. 2, when a large amount of operation information or the like is displayed on the screen of the display 11, it is necessary to make the finger position detectability more precise. In that case, in the optical transmission, the suppression of the divergence of the light S emitted from the light emitting side is made more appropriate, and the focusing of the light S on the light incident side is also made more appropriate, thereby improving the light transmission efficiency. Is called. For this purpose, the dimensions of the first to fourth lens portions 31, 42, 33, 44 are set as follows. That is, in FIGS. 1A to 1C, when the height H of the cores 3A and 3B is within the range of the following (a), the center of curvature M of the lens surface 31a of the first lens portion 31 is described. distance L ₁ from ₁ to the center of curvature M ₂ of the lens surface 42a of the second lens unit 42 is set within the following range (b), the radius of curvature R ₁ of the lens surface 31a of the first lens portion 31 is set within the following range (c), the radius of curvature R ₂ of the lens surface 42a of the second lens unit 42 is set within the following range (d). The distance (L ₂ ) from the center of curvature (M ₃ ) of the lens surface 33a of the third lens portion 33 to the center of curvature (M ₄ ) of the lens surface 44a of the fourth lens portion 44 is as shown in (e) below. The radius of curvature (R ₃ ) of the lens surface 33a of the third lens portion 33 is set within the range of (f) below, and the radius of curvature (R of the lens surface 44a of the fourth lens portion 44 is set within the range. ₄ ) is set within the range of (g) below. The following (a) to (g) are ranges obtained by the present inventor through repeated experiments.
(A) 10 μm ≦ H ≦ 100 μm
(B) 400 μm <L ₁ <10000 μm
(C) 50 μm <R ₁ <6000 μm
(D) 300 μm <R ₂ <10000 μm
(E) 400 μm <L ₂ <10000 μm
(F) 50 μm <R ₃ <6000 μm
(G) 300 μm <R ₄ <10000 μm

  Thereby, in FIG. 3, in the optical waveguide portion A on the light exit side, the divergence suppression of the light S emitted from the lens surface 42a of the second lens portion 42 is made more appropriate, and the emitted light S is converted into parallel light or It is possible to achieve a state close to parallel light, that is, a state where the light does not expand too much and is not excessively focused. As a result, in the optical waveguide portion B on the light incident side, the width of the light incident region in the fourth lens portion 44 can be made more appropriate. On the light incident side, the light S incident on the lens surface 44a of the fourth lens portion 44 is more appropriately focused, and all or most of the incident light S can be propagated into the core 3B.

Note that the dimensions and the like of the rectangular frame-shaped touch panel optical waveguide W ₁ may be set to correspond to the size of the display 11 of the touch panel 10 as shown in FIG. The horizontal length is set to about 30 to 300 mm, respectively, and the frame width is set to about 50 μm to 2 mm. The number of cores 3A that emit light S (cores 3B that receive light S) may be set according to the number of operation contents displayed on the screen of the display 11, for example, 20 to 100 cores. Set to degree.

Next, an example of a method for manufacturing the touch panel optical waveguide W ₁ will be described. 4A to 4D to 5A to 5D referred to in this description are the first to fourth lens portions 31 and 42 shown in FIGS. 1A to 1C. , 33, 44 and their peripheral parts are illustrated. Further, since these shapes and the like are the same on the light emitting side and the light incident side, they are also described.

First, a flat plate-like base 1 [refer to FIG. 4 (a)] to be used in producing the optical waveguide W ₁ for the touch panel. Examples of the material for forming the base 1 include glass, quartz, silicon, resin, metal, and the like. Moreover, the thickness of the base 1 is set in the range of 20 micrometers-5 mm, for example.

  Next, as shown in FIG. 4A, a varnish in which a photosensitive resin, which is a forming material of the under cladding layer 2, is dissolved in a solvent is applied to a predetermined region on the base 1. Examples of the photosensitive resin include a photosensitive epoxy resin. The varnish is applied by, for example, a spin coating method, a dipping method, a casting method, an injection method, an ink jet method, or the like. And it is dried by heat processing of 50-120 degreeC x 10-30 minutes. Thereby, the photosensitive resin layer 2a formed in the under clad layer 2 is formed.

Next, the photosensitive resin layer 2a is exposed with an irradiation beam. For example, visible light, ultraviolet rays, infrared rays, X-rays, α-rays, β-rays, γ-rays, etc. are used as the exposure radiation. Preferably, ultraviolet rays are used. This is because when ultraviolet rays are used, a large curing rate can be obtained by irradiating large energy, and the irradiation device is also small and inexpensive, and the production cost can be reduced. Examples of the ultraviolet light source include a low-pressure mercury lamp, a high-pressure mercury lamp, and an ultrahigh-pressure mercury lamp, and the irradiation amount of the ultraviolet light is usually set within a range of 10 to 10,000 mJ / cm ² .

  After the exposure, heat treatment is performed to complete the photoreaction. This heat treatment is usually performed within a range of 80 to 250 ° C. × 10 seconds to 2 hours. Thereby, the photosensitive resin layer 2 a is formed on the under cladding layer 2. The thickness of the under clad layer 2 (photosensitive resin layer 2a) is usually set within a range of 1 to 50 μm.

  Next, as shown in FIG. 4B, a photosensitive resin layer 3 a formed on the core 3 </ b> A (3 </ b> B) is formed on the surface of the under cladding layer 2. The formation of the photosensitive resin layer 3a is performed in the same manner as the method for forming the photosensitive resin layer 2a formed on the under cladding layer 2 described with reference to FIG. The material for forming the core 3A (3B) is a material having a higher refractive index than the material for forming the under cladding layer 2 and the over cladding layer 4 described later (see FIG. 1C). The adjustment of the refractive index can be performed, for example, by selecting the type of each forming material of the under cladding layer 2, the core 3A (3B), and the over cladding layer 4 and adjusting the composition ratio.

  Next, an exposure mask having an opening pattern corresponding to the pattern of the core 3A (3B) [including the first and third lens portions 31 (33)] is disposed above the photosensitive resin layer 3a. Then, the photosensitive resin layer 3a is exposed to radiation through the exposure mask, and then heat treatment is performed. This exposure and heat treatment are performed in the same manner as the formation method of the under cladding layer 2 described with reference to FIG.

  Subsequently, development is performed using a developing solution to dissolve and remove the unexposed portion in the photosensitive resin layer 3a (see FIG. 4B) as shown in FIG. The photosensitive resin layer 3a remaining on the cladding layer 2 is formed in a pattern of the core 3A (3B). For the development, for example, an immersion method, a spray method, a paddle method, or the like is used. As the developer, for example, an organic solvent, an organic solvent containing an alkaline aqueous solution, or the like is used. Such a developing solution and development conditions are appropriately selected depending on the composition of the photosensitive resin composition.

  After the development, the developer remaining on the surface of the remaining photosensitive resin layer 3a formed in the pattern of the core 3A (3B) is removed by heat treatment. This heat treatment is usually performed within a range of 80 to 120 ° C. × 10 to 30 minutes. Thus, the remaining photosensitive resin layer 3a formed in the pattern of the core 3A (3B) is formed on the core 3A (3B) [including the first and third lens portions 31 (33)]. The thickness (height) of the core 3A (3B) (photosensitive resin layer 3a) is usually set within a range of 10 to 100 μm, and the width of the core 3A (3B) [first and third lens portions 31 (33). ) Other than the substantially fan-shaped widened portion] is usually set within a range of 8 to 50 μm.

  And as shown in FIG.4 (d), the photosensitive resin formed in the over clad layer 4 is apply | coated to the surface of the said under clad layer 2 so that the core 3A (3B) may be coat | covered, and photosensitivity is carried out. A resin layer (uncured) 4a is formed. Examples of the photosensitive resin formed on the over clad layer 4 include the same photosensitive resin as that of the under clad layer 2.

  Next, as shown in FIG. 5A, a forming die 20 for press-molding the over clad layer 4 into a rectangular frame shape is prepared. The mold 20 is made of a material (for example, quartz) that transmits radiation such as ultraviolet rays, and the mold surface 21 has the same shape as the surface shape of the overcladding layer 4 including the second and fourth lens portions 42 (44). The recessed part which consists of is formed. And as shown in FIG.5 (b), with respect to the said photosensitive resin layer 4a, the mold surface (concave part) 21 of the said shaping | molding die 20 is positioned in a predetermined position with respect to the said core 3A (3B). The molding die 20 is pressed, and the photosensitive resin layer 4 a is molded into the shape of the over clad layer 4. Next, the shading mask 25 is placed on the surface portion of the mold 20 corresponding to the portion where the overcladding layer 4 is not formed (the portion where the first and third lens portions 31 (33) are exposed to the outside air). In this state, an irradiation beam such as ultraviolet rays is exposed through the mold 20. Thereafter, heat treatment is performed. This exposure and heat treatment are performed in the same manner as the formation method of the under cladding layer 2 described with reference to FIG. And after demolding, it develops using a developing solution. As a result, as shown in FIG. 5C, the unexposed portion (the portion corresponding to the light shielding mask 25) in the photosensitive resin layer 4a is dissolved and removed, and the first and third lens portions 31 are removed. (33) is exposed to the outside air. After the development, heat treatment is performed. This development and heat treatment are performed in the same manner as the formation method of the core 3A (3B) described with reference to FIG. As a result, a rectangular frame-shaped over clad layer 4 [including the second and fourth lens portions 42 (44)] is obtained. The height of the over clad layer 4 is usually set in the range of 50 to 2000 μm.

  Thus, since the second and fourth lens portions 42 (44) are formed as an extension of the over clad layer 4, the first portion of the end of the core 3A (3B) is formed when the over clad layer 4 is formed. The first and third lens portions 31 (33) and the second and fourth lens portions 42 (44) formed by extending the over clad layer 4 are positioned. When the under clad layer 2 and the over clad layer 4 are made of the same material, the under clad layer 2 and the over clad layer 4 are assimilated at the contact portion.

Thereafter, as shown in FIG. 5D, the undercladding layer 2 and the like together with the base 1 are cut into a rectangular frame shape by punching using a blade die. Thus, a rectangular frame-shaped touch panel comprising the under cladding layer 2, the core 3A (3B) and the over cladding layer 4 (including the second and fourth lens portions 42 (44)) on the surface of the base 1 The optical waveguide W ₁ for manufacturing is manufactured. Then, the touch panel optical waveguide W ₁ is used by being peeled off from the base 1 [see FIG. 1 (c)].

In the first embodiment, the first and third lens portions 31 and 33 at the ends of the cores 3A and 3B are formed in a substantially fan shape that gradually widens toward the end face. if it is possible to perform proper optical transmission between the light emitting side and the light incidence side as W _1, it may be formed the first and third lens portions 31 and 33 with a uniform width.

  In the first embodiment, the second and fourth lens portions 42 and 44 are formed in a band shape, but one piece of the second lens portion 42 is formed for each first lens portion 31. Thus, the second and fourth lens portions 42 and 44 may be formed in a plurality of pieces.

FIGS. 6A and 6B show a second embodiment of the optical waveguide for a touch panel according to the present invention. In the optical waveguide for touch panel W ₂ of this embodiment, the third and fourth lens portions 33 and 44 (see FIGS. 1A to 1C) are formed in the optical waveguide portion B ₁ on the light incident side. In other words, the end surface of the core 3 </ b> B on the light incident side is exposed from the end surface of the over cladding layer 4. Other parts are the same as those of the first embodiment, and the same reference numerals are given to the same parts.

  In this embodiment as well, similar to the first embodiment, the second lens portion 42 of the optical waveguide portion A on the light emitting side emits a divergence in the horizontal direction or the vertical direction with respect to the traveling direction of the light S. Suppressed and emitted. In this embodiment, from the viewpoint of improving the light transmission efficiency, the light is emitted from the first and second lens portions 31 and 42 on the light emitting side so that the light is focused on the end face of the core 3B on the light incident side. It is preferable to squeeze out the light. Also in this embodiment, the position of the finger touching the screen of the display 11 can be accurately detected on the touch panel 10 (see FIG. 2).

  In each of the above embodiments, the under clad layer 2 is formed using a photosensitive resin. Instead, a resin film acting as the under clad layer 2 is prepared, and the under clad layer 2 is used as it is. It may be used. Further, instead of the under-cladding layer 2, a substrate having a metal film (metal material) or a metal thin film (metal material) formed on the surface may be used as a base on which the cores 3A and 3B are formed. .

In each of the above-described embodiments, the touch panel optical waveguides W ₁ and W ₂ have a rectangular frame shape. However, the two L-shaped optical waveguides W ₁ and W ₂ constituting the rectangular frame-shaped touch panel optical waveguides W ₁ and W ₂ are formed. The optical waveguide portions A, B, and B ₁ may be separated. As a manufacturing method thereof, it may be cut into two L-shapes instead of cutting into the rectangular frame shape.

In each of the above embodiments, the touch panel optical waveguides W ₁ and W ₂ are peeled from the base 1 and used in a state where they are formed on the surface of the base 1 without being peeled off. Also good.

  Next, examples will be described. However, the present invention is not limited to the examples.

[Formation material of under clad layer and over clad layer]
By mixing 100 parts by weight of an epoxy resin containing an alicyclic skeleton (manufactured by Adeka, EP4080E) (component A) and 2 parts by weight of a photoacid generator (manufactured by San Apro, CPI-200K) (component B), Materials for forming the under cladding layer and the over cladding layer were prepared.

[Core forming material]
Epoxy resin containing fluorene skeleton (Osaka Gas Chemical Co., Ltd., Ogsol EG) (component C) 40 parts by weight, polyfunctional fluorene epoxy (manufactured by Nagase ChemteX, EX-1040) (component D) 30 parts by weight, 1 , 3,3-tris {4- [2- (3-oxetanyl)] butoxyphenyl} butane (component E) 30 parts by weight and component B: 1 part by weight in 40.8 parts by weight of ethyl lactate A core forming material was prepared.

[Production of optical waveguide for touch panel]
An optical waveguide for a touch panel according to the second embodiment shown in FIGS. 6A and 6B (where the third and fourth lens portions are not formed on the light incident side) was produced as follows. That is, first, the under clad layer forming material was applied to the surface of a polyethylene naphthalate (PEN) film [160 mm × 160 mm × 188 μm (thickness)] with an applicator, and then exposed to 2000 mJ / cm ² of ultraviolet rays. It was. Subsequently, an under clad layer was formed by performing heat treatment at 100 ° C. for 15 minutes. The thickness of the under cladding layer was 20 μm when measured with a contact-type film thickness meter. The refractive index of this under cladding layer at a wavelength of 830 nm was 1.510.

Next, the core forming material was applied to the surface of the undercladding layer by an applicator, followed by drying at 100 ° C. for 15 minutes. Next, a synthetic quartz-based chromium mask (exposure mask) having an opening pattern having the same shape as the core pattern (including the first lens portion) formed thereon is shown in Table 1 below (Examples 1 to 3). ) And corresponding to the dimensions of the first lens part shown in FIG. And after performing the exposure by 4000 mJ / cm < ² > ultraviolet irradiation by the proximity exposure method through the said chromium mask, the heat processing for 80 degreeC x 15 minutes were performed. Next, development was performed using a γ-butyrolactone aqueous solution to dissolve and remove unexposed portions, and then a heat treatment was performed at 120 ° C. for 30 minutes to form a core. The thickness (height) and width (other than the substantially fan-shaped widened portion of the first lens portion) of the core were values shown in Table 1 (Examples 1 to 3) below. Each said dimension was measured with SEM (electron microscope). The refractive index of this core at a wavelength of 830 nm was 1.592.

And the formation material of the over clad layer was apply | coated to the surface of the said under clad layer with the applicator so that a core might be coat | covered. Next, a quartz mold for forming the overcladding layer was prepared corresponding to the radius of curvature (R ₂ ) of the lens surface of the second lens portion shown in Table 2 (Examples 1 to 3) below. These molding dies are formed with a concave portion having a mold surface having the same shape as the surface shape of the overcladding layer (including the second lens portion). Then, the mold was pressed so that the distance (L ₁ ) from the center of curvature of the lens surface of the first lens unit to the center of curvature of the lens surface of the second lens unit was a value shown in Table 2 below. Next, a light shielding mask was placed on the surface portion of the mold corresponding to a portion where the over clad layer was not formed (a portion where the first lens portion was exposed to the outside air). And after exposing by 2000 mJ / cm < ² > ultraviolet irradiation through the said shaping | molding die, the heat processing for 80 degreeC x 15 minutes were performed. Thereafter, the mold was removed. Next, development was performed using a γ-butyrolactone aqueous solution to dissolve and remove the unexposed portion, and then a heat treatment was performed at 120 ° C. for 30 minutes. As a result, an over clad layer including the second lens portion was obtained. When the height of the over clad layer was measured with a microscope (manufactured by Keyence Corporation), the height was 1000 μm. Further, the refractive index of the over cladding layer at a wavelength of 830 nm was 1.510. The width (D ₁ ) of the outside air portion exposing the first lens portion on the light emitting side and the width (E ₁ ) of the gap between the lens surface of the first lens portion and the second lens portion are as follows: This is shown together with 2.

  Then, it is cut into two L-shaped optical waveguide portions together with the PEN film by punching using a blade mold, and an L-shaped optical waveguide portion with a PEN film (external dimensions: 66.3 mm × 70.0 mm, L-shaped Two line widths: 10 mm) were obtained.

[Evaluation]
The obtained two L-shaped optical waveguide portions with PEN film were arranged to face the surface of the glass epoxy substrate so as to form a square frame. Then, alignment was performed using a microscope so that the optical axes of the opposed light emitting side core and the light incident side core coincide. Then, a predetermined portion of the outer edge portion of the L-shaped optical waveguide portion of the light emitting side, a light-emitting element, a VCSEL (Opt o well Ltd.) for emitting light having a wavelength of 850 nm, through the ultraviolet curing adhesive Connected. A CMOS linear sensor array (manufactured by TAOS) was connected as a light receiving element to a predetermined portion of the outer edge of the L-shaped optical waveguide portion on the light incident side via an ultraviolet curable adhesive. And the control part of the said light receiving element was connected to the USB type | mold taking-in unit (made by National Instruments) via the flexible printed circuit board, and also connected to the computer via the USB port. Then, light having an intensity of 2 mW (wavelength 850 nm) was emitted from the light emitting element, and operation evaluation as a touch panel was performed.

  As a result, in all of Examples 1 to 3, the light emitted from the light emitting element passes through the L-shaped optical waveguide portion on the light exit side, crosses the coordinate input region in a lattice shape, and then enters the light. It was confirmed that it passed through the L-shaped optical waveguide portion on the side and finally reached the light receiving element. Furthermore, when the coordinate input area was touched with a finger, the coordinates were displayed on the computer screen, and it was confirmed that the coordinate input area was operated as a touch panel.

BRIEF DESCRIPTION OF THE DRAWINGS The 1st Embodiment of the optical waveguide for touchscreens of this invention is shown typically, (a) is the top view, (b) is an expansion of the edge part of the core enclosed by the round part C of (a). It is a figure, (c) is XX sectional drawing of (b). It is a perspective view which shows typically the touchscreen using the said optical waveguide for touchscreens. The light emission state in the said optical waveguide for touchscreens is shown typically, (a) is the top view, (b) is XX sectional drawing of (a). (A)-(d) is explanatory drawing which shows typically the manufacturing method of the said optical waveguide for touchscreens. (A)-(d) is explanatory drawing which shows typically the continuation of the manufacturing method of the said optical waveguide for touchscreens. A second embodiment of the touch panel optical waveguide of the present invention schematically shown, (a) is a its plan view, (b) the light incident side of the core surrounded by a circle portion C ₁ of the (a) It is an expanded sectional view of the edge part. The conventional optical transmission apparatus is shown typically, (a) is the top view, (b) is XX sectional drawing of (a).

Explanation of symbols

3A, 3B Core 4 Overclad layer 31 1st lens part 33 3rd lens part 42 2nd lens part 44 4th lens part 31a, 33a, 42a, 44a Lens surface

Claims (6)

A core that is patterned on the surface of the substrate and an overcladding layer that is formed by molding in a state of covering the core, and is disposed along the peripheral edge of the screen of the touch panel display and emits light. The end is positioned on one side of the display screen, the end of the core that receives the emitted light is positioned on the other side of the display screen, and the end of the core that emits the light is over the in a state where the missing recesses odor Te was exposed to the outside air of the cladding layer formed on the first lens unit, the lens surface at the first lens portion is formed in plan view an arc shape which bulges outwardly, the first lens unit portion of the over cladding layer facing at a lens surface and a gap is formed in the second lens unit corresponding to the first lens unit, the lens surface at the second lens unit A method of manufacturing a filter touch panel optical waveguide is formed in a side cross-sectional arc-shape bulges on the side, the mold used for the molding of the over cladding layer is made of a material permeable to the radiation A concave portion having a mold surface corresponding to the surface shape of the over clad layer is formed, and one side portion of the concave portion is formed in the lens curved surface shape of the second lens portion. The manufacturing method of the optical waveguide for touchscreens characterized by performing through the process of following (a)-(d) .
(A) A step of forming an uncured photosensitive resin layer for forming an overcladding layer on the surface of the substrate in a state where the core is covered.
(B) The concave portion of the molding die is pressed by pressing the concave portion of the molding die against the photosensitive resin layer in a state where the curved surface portion of the concave portion of the molding die is disposed so as to correspond to the first lens portion of the core. A step of closely contacting the opening surface of the substrate to the surface of the substrate.
(C) A light-shielding mask is placed on the surface portion of the molding die corresponding to the defective recess formation scheduled portion, and in that state, the photosensitive resin layer is exposed with irradiation rays through the molding die, and the exposed portion Is a process of forming an overcladding layer by curing.
(D) After demolding, the unexposed portion of the photosensitive resin layer corresponding to the light shielding mask is removed by development to form the defective recess, and the first lens portion of the core is formed from the defective recess. The process of exposing to the outside air. The first lens unit, a gradually widening to a substantially fan shape, a touch panel of the circular surface according to claim 1, wherein you formed on the lens surface in the substantially fan shape toward the end face of the second lens portion Manufacturing method of optical waveguide. Formed in the third lens unit in a state of being exposed to the outside air Te other defects recess smell the emitted end the upper Kio over bar cladding layer of the core which light enters the lens surface at the third lens unit is on the outside It headed formed in a planar arc-shaped warp, part of the over cladding layer facing at a lens surface and gaps of the third lens portion is formed in the fourth lens unit corresponding to the third lens unit, 3. The method of manufacturing an optical waveguide for a touch panel according to claim 1, wherein a lens surface of the fourth lens portion is formed in an arc shape in a side sectional view that warps outward. A molding die used for molding is made of a material that transmits radiation, a recess having a mold surface corresponding to the surface shape of the over clad layer is formed, and the other side of the recess is formed by the fourth lens unit. Lens curved shape is formed, the formation of the over cladding layer, the step according to claim 1 or 2 Preparation of optical waveguide for a touch panel according performed via the following (e) ~ (h).
(E) A step of forming an uncured photosensitive resin layer for forming an overclad layer on the surface of the base body in a state of covering the core.
(F) The concave portion of the molding die with respect to the photosensitive resin layer in a state where the lens curved surface shape portion of the fourth lens portion of the concave portion of the molding die is disposed so as to correspond to the third lens portion of the core. And pressing the opening surface of the recess into close contact with the surface of the substrate.
(G) A light-shielding mask is placed on the surface portion of the mold corresponding to the other defective recess formation scheduled portion, and in that state, the photosensitive resin layer is exposed with irradiation rays through the mold, A step of curing the exposed portion to form an overcladding layer.
(H) After demolding, by development, the unexposed portion of the photosensitive resin layer corresponding to the light-shielding mask is removed to form the other defective concave portion, and the third lens of the core is formed from the defective concave portion. The process of exposing the part to the outside air. The third lens unit, a gradually widening to a substantially fan shape, a touch panel of the circular surface according to claim 3, wherein you formed on the lens surface in the substantially fan shape toward the end face of the fourth lens portion Manufacturing method of optical waveguide. The substrate, the under cladding material or any method of the optical waveguide for the touch panel according to one of 請 Motomeko 1-4 ing a metallic material. A touch panel optical waveguide produced by a production method of the claim 1 Symbol placement touch panel optical waveguide, the core is patterned on the surface of the substrate, the photosensitive formed by molding in a state as to cover the cores a sexual resin of the over-cladding layer, the ends of the core for emitting light is formed in the first lens unit, the lens surface is formed in plan view an arc shape which bulges outwardly in the first lens unit A portion of the overcladding layer corresponding to the first lens portion of the core is formed in a defective concave portion that is a removal mark by development, and the first lens portion is exposed to the outside air in the defective concave portion, and the first lens A portion of the over clad layer facing the lens surface of the portion with a gap is formed to form a second lens portion corresponding to the first lens portion, and the lens surface in the second lens portion is outside Headed warped sectional side view touch panel optical waveguide, characterized in that it is formed in a circular arc shape.

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